Trench shoring device



Jan. 25, 1966 BENNETT 3,230,720

TRENGH SHORING DEVICE Filed May 2, 1960 2 Sheets-Sheet 1 INVENTOR. DAR/EN BENNETT H/S A T TO/PNEVS 2 Sheets-Sheet 2 Filed May 2, 1960 83 82 e! as DAR/EN BENNETT E m M 2 P/ 4 M I. 6 4 R. k 2 b m 8 g 2 N /Wl J w 2Q W. M N 3 I 6 a w A 6 r W I\ B) l .J m m g J M fi 3 4 3 H w E 6 F n United States Patent O 3,230,720 TRENCH SHORHNG DEVItCE Darien Bennett, Santa Clara, Calif., assignor to Sigma Engineering Corporation, San 505e, Calif. Filed May 2, 1960, Ser. No. 26,936 3 Claims. (Cl. 61-41) This invention relates to shoring devices and more particularly to certain novel improvements in portable trench shoring devices.

In the matter of trenching shoring it is customary to provide pad-like planks or the like on opposite vertical walls of the trench and bracing them one to another by forcing strut members between them. Such shoring units are placed at spaced intervals along the trench, the spacing being dependent upon the type of soil to be shored and the depth of the trenching therein.

In order to quickly insert shoring units with a minimum of disturbance to the walls of a trench, collapsible type shoring has been conceived and developed. A common form of collapsible shoring is disclosed in United States Patent No. 2,482,367 to Ravers which shows toggle braces associated with a screw rod for spreading and contracting the shoring planks or side pads.

The present invention relates to improvements in collapsible shoring in whichthe pads and cross braces are pivotally connected in the form of a parallelogram. In this connection it is a further object to provide expandable cross braces in such an arrangement.

Another object is to provide means in combination with the pivotal connection between the cross braces and pads for limiting movement thereof beyond a rectangular disposition relative to each other.

It is a further object to provide means for expanding the cross braces of the parallelogram shoring for spreading the pads relative to each other. This object entails the provision of hydraulically expandable cross bracing in a hydraulic system of conduits coordinated with the articulatable components of the shoring to facilitate operation thereof.

It is another object to provide preformed extruded metal pads so constructed as to'be light of weight yet sturdy and rigid to withstand the stresses afforded during their load bearing function. Such preformed pads are so constructed as to facilitate the provison of trunnion supports at the pivotal connections between them and the cross braces.

It is yet another object to provide a collapsible shoring device capable of being inserted, positioned and expanded into a trench and shoring condition by one man only. In connection with this object it is'a further object to provide shoring which eliminates the necessity of a man or men to enter the trench while inserting, positioning an dexpanding the shoring device into shoring condition therein. This object entails the provision of shoring which can be placed and established in shoring condition immediately behind a trencher or digger in a minimum of time and man hours and with maximum safety to the workmen.

These and other objects and advantages of the present invention will become apparent from a reading of the following description taken in the light of the accompanying drawings in which:

FIG. 1 is an exploded perspective view of components of the shoring embodying the present invention.

FIG. 2 is a section through a trench into which shoring of the present invention is being lowered in collapsed condition.

FIG. 3 is a view similar to FIG. 2 with the shoring of the present invention in effective shoring position.

FIG. 4 is a section through the shoring as shown in 3,230,720 Patented Jan. 25, 1966 FIG. 3, at larger scale and as seen from line 44 thereof. FIG. 5 is a side view of the components shown in FIG. 4 and taken along line 5-5 thereof.

FIG. 6 is an enlarged fragmentary detail of the piston arrangement between the cylinder and ram of FIG. 5. In general the shoring unit 10 comprises a pair of side members referred to hereinafter as pads 11 and 12 each pivotally connected adjacent its upper and lower ends, as at 13, 14, 15 and 16 (FIGS. 2 and 3) to upper and lower cross braces 17 and 18, respectively. Asbestseen in FIGS. 2 and 3 the arrangement is such that the unit 10 forms a parallelogram in which the pads will remain parallel while being moved toward and from each other as the braces swing in unson in parallel relation to each other between the pads. In addition to the foregoing it will be noted that the cross braces 17 and 18 are expandable and retractable for spreading and contracting ber 20 having a cross sectional configuration providing a web 21 from which a pair of integral flanges 22 and 23 extend in spaced and parallel relation with respect to each other on either side of an axial line L- which is transverse to the plane in which the web 21 extends. These flanges 22 and23 are equidistant from the axial line -L and in effect each forms the leg of a T shape in which the cap of the T is aligned and integrally formed with that of the other. The arrangement is such that the flanges 22 and 23 with the connected halves of the T head of each form a channel C between the outer edges 24 and 25 of the web member 21. The outer edges 24' and 25 are each rigidified and strengthened by a terminal bead or enlargement which extends from the web in the same direction as do the flanges 22 and 23.

Each of pads 11 and 12 (members 20) are made from a lightweight material, preferably an aluminum alloy having high stress characteristics. The member 20 as above described is so configurated as-to be conducive 'toformation by extrusion and therefore will not only be light of eluding a cylinder 31, a piston 32 and a ram 33 providing an expandable-retractable brace. As previously pointed out each brace is pivotally connected to both pads to facilitate articulation of the shoring unit 10. V

The pivotal connections between the braces 17 and 18 and the pads 11 and 12 are quite similar in that the flanges 22 and 23 of each pad is provided with aligned bores 35 and 36, respectively. The aligned bores at 13 on the pad- 11 are at. a fixed distance from the top 37 thereof and the'bores at 14 on the pad 12 are at the same fixed distance from the top 38 thereof. By the same token the bores at 15 on the pad 11 are at a fixed or predetermined distance from the bottom end 39 of pad 11 and the bores at 16 on pad 12 are the same fixed distance from the,

bottom end 39' thereof. The arrangement is such that when the braces and pads are in the form of a rectangle, the braces will be normal to the pads.

The pivotal connections between the pads and braces at 13, 14, 15 and 16 are similar in that each comprises a T headed boss or bushing 40 on the free end of the cylinder 31 and I head boss 41 on the end of the ram 33. Both bosses 40 and 41 are dimensioned to extend between the flanges 22 and 23 of the pad to which they are to be connected. The length of the boss 40 or 41 is such as to leave a space at each end thereof to receive a bearing lug 42 between the end of the boss and the adjacent inner face of the flanges 22 or 23 as the case may be.

These bearing lugs 42 are alike in that each has a flat base 43 disposed to bear against the web 21 of the structural member 20 (pad 11 or 12) and has a bore 44 so positioned relative to the base 43 as to align axially with the bore 35 or 36 as the case may be in the particular flange 22 or 23 against which the lug 42 rests. These lugs 42 thereby cooperate with the flanges 22 and 23 in providing trunnion support for the bosses 40 or 41 on the cross braces. In other words, since the flanges are generally narrow the lugs 42 serve therewith to provide sufficient bearing for the pivotal connection now to be explained.

As best seen in FIGS. 1 and 2 the boss 40 or 41 likewise has an axial bore 45-45, respectively of the same diameter as the bore 44 in the lugs 42 and the bores 35 and 36 in the flanges 22 and 23 so as to receive a stud shaft or pin 46. The pin 46 has transverse small bores adjacent each its ends, i.e., those portions thereof extending beyond the flanges 22 and 23, for receiving a cotter and 13 are contracted and swung upwardly at an obtuse angle relative to the pad 11. The pad 12 is thus elevated slightly so that its upper end 38 is higher than the upper end 37 of the pad 11. A man standing on earth level E adjacent the trench T can grasp the handle 68 of pad 12 with one hand and by means of a hook and rod or cable H engaged in the other handle can suspend the other pad 11 while lowering the entire unit into the trench T.

When the lower end 33 of pad 11 is at the desired posh tion in the trench, the mans grasp on handle 68 is released so that the pad 12 is free to fall by gravity. The pad 12 is guided by the pivoted braces 17 and 18 so as to remain parallel to the pad ll. When the pad 12 beby means of the hook and rod H. This is'to say, as the pin 47 by which the pin 46 is held in juxtaposition relative to the pad and boss to be pivotally connected.

The boss 40 on the end of the cylinder is formed with a casting 48 integrally with a shank stem 49 and cap 50 the latter of which is secured as by press fit and welding to the open end of the cylinder 30. The shank stem 49 has lateral bracket webs 51 and 52 formed integrally therewith and with the boss 40 and the cap 50 for transmitting compressive load from the cylinder uniformly to the boss 40. The casting 48 has a bias block 53 formed integrally with and at the intersection between the shank 49 and cap 50. This block 53 has a passage 54 formed therethrough communicating with the interior of the cylinder 30.

On the opposite end of each brace 17 and 18 the T head 41 is formed with a casting 60 including a shank 61 terminating in a cup 62 dimensioned to receive the free end of the ram 33 to which it is to be connected. The connection is made by a bayonet and slot arrangement 63-64, respectively. The bushing boss 41 has a foot portion 65 formed integrally therewith. This foot portion 65 has a bearing face 66 in spaced relation to the axis a of the bore 45' in the boss 41 a distance comparable to the distance between such axis and the inner face of the web 21 on the adjacent pad 13. The bearing face 66 is disposed perpendicular to the bearing axis -bof the shank 61 of the casting 60 so that when the latter is disposed normal to the pad 13 the foot 65 will limit further pivotal movement of the pad in an anti-clockwise direction (FIGS. 2 and 5) relativeto the pin 46. The importance of this feature will become apparent during explanation of the placement of the shoring unit within a trench.

The upper ends 37 and 38 of each pad 11 and 12, respectively, have a handle 6'7 and 68, respectively, secured thereto. These handles 67 and 68 are identical (FIG. 1) in that each consists of a U-shaped bar 69' having a bight 70, parallel legs 71 and 72 from which extend inturned pinion ends 73 and 74, respectively. These legs 71 and 72 straddle the flanges 22 and 23 of the pad, 11 or 12 as the case may be, and the pinion ends 73 and 74 extend into holes 75 and 76, respectively, bored through the respective flanges 22 and 23 in axial alignment with each other. In this manner the handles 67 and 68 are each pivotally connected to the upper ends of their respective pads 11 and 12 to facilitate manipulation thereof.

Referring now to FIG. 2 it will be noted that when the unit 10 is in collapsed condition the hydraulic braces 17 man supports the rod H with one hand the entire shoring unit will hang in open rectangular condition at the elevation desired. With his other or free hand the man manipulates a control valve 88 by which to expand the cross braces 17 and 18- Expansion of the cross braces 17 and 18 is accomplished hydraulically by a system of conduits 77 associated with each shoring unit 10 for ready connection to a source of hydraulic fluid 78 (FIGS. 2 and 3).

The conduit system 7'7 comprises a main line 80 having one side 31 of a coupling unit 82 connected to its upper end. The coupling unit 82 is preferably of the type described and shown in United States Patent No. 2,548,- 528 which issued to Fred E. Hansen on April 10, 1951. The opposite side 83 of the coupling unit 82 is connected to the free end of a feed line 84 coming from the source of hydraulic fluid 78.

The main line 80 of the conduit system 77 is mounted on the pad 11 which is the first to enter the trench. The line 86 enters the pad 11 between the flanges 22 and 23 and passes through the flange 23 well above the pivot point 13 for the upper brace 17. Below the pivot point 13 the line 30 again enters the channel C provided between the flanges 22 and 23 where the line 89 is connected to a block 85 secured to the web 21 .of the pad v11. The block 85 has a passage formed therein communicating with the line 80 and with a flexible hose 86 having its opposite end secured in the tapped end of the passage 54 formed in the casting 48 on the end of the cylinder 31. An auxiliary line 80 having communication with the passage within the block 85 extends therefrom and through the flange 23, line 81) being secured by cups $7 to the flange 23 exteriorly of the channel C as best seen in FIGS. 4 and 5. The terminal end of auxiliary line 8%) passes through the flange 23 below the pivot point 15 of the lowermost cross brace 18 where the line is secured to a block secured to the pad 11. The block 85 has an internal passage communicating with a flexible hose 86 the opposite end of which is secured in the tapped end of the passage 54 formed in the casting 48 on the cylinder 31 of the lower brace 18.

The main line 8% (FIG. 3) has a hand controlled valve 88 disposed therein adjacent the coupling 82. Consequently when the coupling connection 82 is made between the line 80 and the source of hydraulic fluid 78, the attendant, by manipulation of the valve 88 admits fluid under pressure into the system 77 whereby fluid under pressure enters each of the hydraulic jacks 30 to force the ram 33 of each outwardly relative to its cylinder 31. The cross braces 17 and 18 are thereby expanded in unison to spread the pads 11 and 12 into load bearing contact with the sides of the trench T. Once this expansion is accomplished the valve 88 is shut off and the coupling 82 disconnected so that the source of hydraulic fluid can be shifted to the position of the next shoring unit 10 to be expanded.

While I have described my new shoring unit in specific detail it will be appreciated by those skilled in the art that the same is susceptible to modification, alteration and/or variation without departing from the spirit of my invention. I therefore desire to avail myself of all modifications, alterations and/or variations as fairly come Within the purview of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. A trench shoring device comprising a pair of elongated pads disposed in opposed upright parallelism having outer surfaces adapted to engage the side walls of a trench and having their inner surfaces disposed in oppositely facing unobstructed relation and each of said inner surfaces being provided With a pair of spaced apart reinforcing flanges, a pair of expandable braces each having its opposite ends connected to said flanges to form with the pads a frame of generally quadrilateral shape in side elevation, said connections being pivotal and providing for a substantial range of free swinging movement of one of said pads and said braces from a collapsed condition of the device in which the pads and braces are oblique-angularly related and the quadrilateral shape is that of a relatively fiat parallelogram to an expanded condition of the I device in which the pads and braces are right-angularly related and the quadrilateral shape is that of a rectangle, and means connected to said braces for simultaneously operating them to expanded or contracted condition.

2. A trench shoring device as claimed in claim 1 including means on that end of each of said braces engaging one of said pads for limiting pivotal movement thereof beyond right-angular relation with said braces.

3. A trench shoring device as claimed in claim 1 in which said flanges form a medial elongated channel and the ends of said braces are pivotally mounted in said channels, a bearing boss is provided on one end of each of said braces and is disposed transversely between the fianges of one of said pads, and a foot portion is formed on at least one of said bearing bosses having a bearing face disposed perpendicular to the longitudinal axis of the brace of which it is a part and offset laterally relative to said axis for bearing against the adjacent channel thereby to limit pivotal movement of the adjacent pad beyond right-angular relation with said brace.

References (Iiteri by the Examiner UNITED STATES PATENTS 503,437 8/1893 Pilcher 61-39.1 1,799,089 3/1931 Clark 182-l60 2,482,367 9/1949 Ravers 6141 2,795,935 6/1957 Fitzgerald 6145.2 2,922,283 1/1960 Porter 61-41 3,029,667 4/ 1962 Millerbernd 6141 CHARLES E. OCONNELL, Primary Examiner.

JACGB L. NACKENOFF, WILLIAM I. MUSHAKE,

Examiners. 

1. A TRENCH SHORING DEVICE COMPRISING A PAIR OF ELONGATED PADS DISPOSED IN OPPOSED UPRIGHT PARALLELISM HAVING OUTER SURFACES ADAPTED TO ENGAGE THE WALLS OF A TRENCH AND HAVING THEIR INNER SURFACES DISPOSED IN OPPOSITELY FACING UNOBSTRUCTED RELATION AND EACH OF SAID INNER SURFACES BEING PROVIDED WITH A PAIR OF SPACED APART REINFORCING FLANGES, A PAIR OF EXPANDABLE BRACES EACH HAVING ITS OPPOSITE ENDS CONNECTED TO SAID FLANGES TO FORM WITH THE PADS A FRAME OF GENERALLY QUADRILATERAL SHAPE IN SIDE ELEVATION, SAID CONNECTIONS BEING PIVOTAL AND PROVIDING FOR A SUBSTANTIAL RANGE OF FREE SWINGING MOVEMENT OF ONE OF SAID PADS AND SAID BRACES FROM A COLLAPSED CONDITION OF 